 Let me read one source that talked about this, when it was in place. It was in place for about, actually, 10th, 11th century. Ancient custom had people kissing the foot and the hand and the knee, and even sometimes the elbow of a superior, but you kissed the cheek of a friend, which was what took place. This wasn't some ceremony. This wasn't some ritual. This was spontaneous, casual affection practiced man to man and woman to woman.